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Chapter 5
Mapping between Streams
Similar to connecting nodes, this method of data mapping does not require you to set essential
fields beforehand. With this method, you simply connect from one stream to another using Map to
from the Data Mapping pop-up menu. This type of data mapping is useful for mappin g to terminal
nodes and copying and pasting between streams. Note: Using the Map to option, you cannot map
to Merge, Append, and all types of source nodes.
Figure 5-47
Mapping a stream from its Sort node to the Typenode of another stream
ToMap Data between Streams
ERight-click the node that you want to use for connecting to the new stream.
EOn the menu, click:
Data Mapping > Map to
EUse the cursor to select a destination node on the target stream.
EIn the dialog box that opens, ensure that fields are properly matched and click OK.
Specifying Essential Fields
When mapping to an existing stream, essential fields will typically be specified by the stream
author. These essential fields indicate whether a particular field is used in downstream operations.
For example, the existing stream may build a model that uses a field called Churn. Inthis stream,
Churn is an essential field because you could not build the model without it. Likewise, fields used
in manipulation nodes, such as a Derive node, are necessary to derive the new field. Explicitly
setting such fields as essential helps to ensure that the proper fields in the n ew source node are
mapped to them. If mandatory fields are not mapped, you will re ceive an error message. If you
decide that certain manipulations or output nodes are unnecessary, you can delete the nodes from
the stream and remove the appropriate fields from the Essential Fields list.